Lua: use sha1 instead of hashname.

Better to leave control over the extension to the user.

doc/lua-filters.md

@@ -1130,18 +1130,17 @@ storage. The "media bag" is used when pandoc is called with the
         local filename = "media/diagram.png"
         local mt, contents = pandoc.mediabag.lookup(filename)
 
-[`hashname (mime_type, contents)`]{#mediabag-hashname}
+[`sha1 (contents)`]{#mediabag-sha1}
 
-:   Returns a filename with a basename based on the SHA1 has of the
-    contents and an extension based on the mime type.
+:   Returns the SHA1 has of the contents.
 
     Returns:
 
-    -   Filename based on SHA1 hash.
+    -   SHA1 hash of the contents.
 
     Usage:
 
-        local fp = pandoc.mediabag.hashname("plain/text", "foobar")
+        local fp = pandoc.mediabag.sha1("foobar")
 
 [`fetch (source, base_url)`]{#mediabag-fetch}
 

src/Text/Pandoc/Lua/PandocModule.hs

@@ -47,7 +47,7 @@ import Text.Pandoc.Class (readDataFile, runIO,
 import Text.Pandoc.Options (ReaderOptions(readerExtensions))
 import Text.Pandoc.Lua.StackInstances ()
 import Text.Pandoc.Readers (Reader (..), getReader)
-import Text.Pandoc.MIME (MimeType, extensionFromMimeType)
+import Text.Pandoc.MIME (MimeType)
 import Data.Digest.Pure.SHA (sha1, showDigest)
 
 import qualified Foreign.Lua as Lua
@@ -93,7 +93,7 @@ pushMediaBagModule commonState mediaBagRef = do
   addFunction "lookup" (lookupMediaFn mediaBagRef)
   addFunction "list" (mediaDirectoryFn mediaBagRef)
   addFunction "fetch" (fetch commonState mediaBagRef)
-  addFunction "hashname" hashnameFn
+  addFunction "sha1" sha1HashFn
   return ()
  where
   addFunction name fn = do
@@ -101,20 +101,12 @@ pushMediaBagModule commonState mediaBagRef = do
     Lua.pushHaskellFunction fn
     Lua.rawset (-3)
 
-hashnameFn :: OrNil MimeType
-           -> BL.ByteString
+sha1HashFn :: BL.ByteString
            -> Lua NumResults
-hashnameFn nilOrMime contents = do
-  Lua.push (getHashname (toMaybe nilOrMime) contents)
+sha1HashFn contents = do
+  Lua.push $ showDigest (sha1 contents)
   return 1
 
-getHashname :: Maybe MimeType -> BL.ByteString -> String
-getHashname mbMime bs =
-  let ext = fromMaybe ""
-              (('.':) <$> (mbMime >>= extensionFromMimeType))
-      basename = showDigest $ sha1 bs
-  in  basename ++ ext
-
 insertMediaFn :: IORef MB.MediaBag
               -> FilePath
               -> OrNil MimeType